KR101539663B1 - Flame retardant expanded polystyrene particle using wastes and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a flame retardant polystyrene-based foaming particle using a waste and a manufacturing method thereof. The flame retardant polystyrene-based foaming particle of the present invention comprises: a styrene-based polymer; a first flame retardant which is separated from a waste wire; and a second flame retardant, wherein the second flame retardant contains aluminum hydroxide and sulfur. Accordingly, the present invention has an excellent flame retardant property, but also high economic efficiency.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a flame retardant polystyrene-

The present invention relates to a flame-retardant polystyrene-based expanded particle using waste, and more particularly to a flame-retardant polystyrene-based expanded particle having excellent flame retardancy and high economic efficiency by using waste such as a waste wire, ≪ / RTI >

Expanded polystyrene (EPS) is useful as a thermal insulation material for buildings. Expanded polystyrene products (typically, styrofoam) are advantageous in terms of lightweight properties and ease of processing, as well as being highly heat-insulating. In general, foamed polystyrene products are produced by forming polystyrene particles in a bead shape, heating them to foam (primary foaming), and then applying steam or heat in a molding machine to form panels or the like Molding method. At this time, the foaming (secondary foaming) proceeds by steam even during the molding process.

However, the conventional general expanded polystyrene is very vulnerable to heat, so that it is easily burned, and toxic gas is generated when it is burned. Accordingly, various techniques have been attempted to improve the flame retardancy of expanded polystyrene. In most cases, the use of flame retardants. Korean Patent No. 10-0305711, for example, discloses a technique for coating a surface of expanded polystyrene particles with a flame retardant such as a halogen-based compound or phosphorus compound, and Korean Patent Laid-Open No. 10-2001-0072979 discloses a method for coating an expanded polystyrene composition A method of adding a flame retarding agent of a brominated organic compound to the surface of the substrate is proposed.

Korean Patent No. 10-0991189 discloses a technique of applying a flame retardant component composed of water glass, sodium carbonate, sodium sulfite, sodium hydrogencarbonate, and magnesium carbonate. In Korean Patent No. 10-1281577, expanded graphite is added Technology is presented.

However, conventional techniques including the above-mentioned prior art documents are difficult to exhibit an excellent flame retarding effect in terms of suppressing smoke generation and the like. Also, generally, the flame retardant is expensive. Accordingly, the flame-retarded expanded polystyrene according to the prior art has a problem in that the cost is low due to its high price, and in the case of the final molded product, the mechanical properties such as tensile strength are deteriorated.

Korean Patent No. 10-0305711 Korean Patent Publication No. 10-2001-0072979 Korea Patent No. 10-0991189 Korean Patent No. 10-1281577

Accordingly, it is an object of the present invention to provide flame retardant polystyrene foam particles having excellent flame retardancy with high economic efficiency, and a process for producing the same.

Another object of the present invention is to provide flame retardant polystyrene foam particles having excellent flame retardancy and high mechanical strength such as tensile strength, and a process for producing the same.

Additionally, it is an object of the present invention to provide a method for producing flame retardant polystyrene-based expanded beads, which comprises separating a resin and a flame retardant from a waste wire, respectively, and a separation process with improved separation efficiency.

According to an aspect of the present invention,

Styrene type polymers;

A first flame retardant separated from the waste wire; And

A second flame retardant,

The second flame retardant provides flame retardant polystyrene type expanded particles containing aluminum hydroxide and sulfur.

According to a preferred embodiment, the flame retardant polystyrene type expanded particles according to the present invention further comprise a third flame retardant, and the third flame retardant is selected from organic materials having an acetyl group. At this time, the second flame retardant is dispersed in the polystyrene-based expanded particles, and the first and third flame retardants are coated on the surface of the polystyrene-based expanded particles.

Further, according to the present invention,

Separating the first flame retardant from the waste wire;

Obtaining polystyrene-based expanded particles from a mixture comprising a styrene-based polymer and a second flame retardant; And

Coating the surface of the polystyrene-based expanded particle with a first flame retardant agent separated from the waste wire,

The second flame retardant agent provides a method for producing flame retardant polystyrene foam particles containing aluminum hydroxide and sulfur.

Further, according to the present invention,

Separating the first flame retardant from the waste wire;

Obtaining polystyrene-based expanded particles from a mixture comprising a styrene-based polymer and a second flame retardant;

Obtaining a flame retardant coating liquid comprising a third flame retardant and a first flame retardant separated from the waste wire; And

And coating the surface of the polystyrene type expanded particles with the flame retardant coating liquid,

Wherein the second flame retardant contains aluminum hydroxide and sulfur,

And the third flame retardant is selected from an organic substance having an acetyl group.

According to a preferred embodiment of the present invention, the step of separating the first flame retardant from the waste wire further comprises:

Dissolving a waste wire in an organic solvent to obtain a coating mixture containing a resin and a first flame retardant from a waste wire; And

And a precipitating and separating step of allowing the coating mixture to precipitate the first flame retardant through a difference in specific gravity and then separating the first flame retardant from the coating mixture.

The organic solvent is a water-soluble organic solvent having a higher solubility in water than a resin constituting the waste wire,

Wherein the precipitating and separating step includes: a first step of adding water to the coating mixture so that the resin floats up to the upper layer and the first flame retardant is precipitated; And

A resin from the coating mixture; A mixed solution containing an organic solvent and water; And a second step of separating the first flame retardant.

According to the present invention, an excellent flame retardancy can be realized with high economic efficiency.

Specifically, according to the present invention, waste (recycled resources) separated from the pulsed electric wire is used as a flame retardant and has high economic efficiency. In addition, aluminum hydroxide (Al (OH) ₃ ) contained in the second flame retardant generates moisture (H ₂ O) to suppress ignition and heat generation, and at the same time, sulfur And the like, while suppressing generation of smoke and the like, thereby achieving excellent flame retardancy.

In addition, according to the present invention, when the third flame retardant selected from organic materials is coated according to the embodiment, the flame retardancy is improved and the film has excellent mechanical properties such as tensile strength and the like.

In addition, according to the present invention, the separation step of separating the resin and the flame retardant from the waste wire is improved, and the resin constituting the waste wire as well as the flame retardant can be efficiently recycled.

As used herein, the term "and / or" is used to include at least one of the preceding and following elements. The term "one or more" as used in the present invention means one or more than two.

Also, in the present invention, terms such as "first", "second" and "third" are used to distinguish one element from another, no.

Hereinafter, an exemplary embodiment of the present invention will be described. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of exemplary embodiments of the present invention, detailed descriptions of known general functions and / or configurations are omitted.

The present invention provides, in one form, flame retardant polystyrene foam particles and a process for producing the same. The present invention also provides a molded article comprising the flame-retardant polystyrene type expanded particles and a method for producing the same, according to another aspect.

The flame-retardant polystyrene-based expanded particles according to the present invention include styrene-based polymers; A first flame retardant separated from the waste wire; And a second flame retardant. At this time, the second flame retardant contains aluminum hydroxide (Al (OH) ₃ ) and sulfur (S). In the present invention, "flame retarding" includes the meaning of difficulty in generating a fire, prevention of spread of a fire, suppression of generation of smoke (flame retardation), and / or fire prevention.

The shape and size of the flame-retardant polystyrene type expanded particles (hereinafter, abbreviated as "expanded particles") according to the present invention are not limited. The expanded particles according to the present invention may have shapes such as beads, pellets and / or flakes, for example. In one example, the expanded particles according to the present invention may have bead shapes such as spherical, elliptical and / or polygonal. In the present invention, spherical (and elliptical) does not mean only a complete spherical (and oval). The expanded particles according to the present invention may have a size of, for example, 0.2 to 2 cm in diameter, but are not limited thereto.

The styrene type polymer is a polystyrene type resin, and is not particularly limited as long as it is a polymer containing at least one styrene group in the molecule. The styrene-based polymer may be selected from homopolymers and / or copolymers of styrene-based monomers. The styrenic monomers include, for example, styrene; Alkylstyrenes such as ethylstyrene, dimethylstyrene and para-methylstyrene; Alpha-alkylstyrenes such as alpha-methylstyrene, alpha-ethylstyrene, alpha-propylstyrene and alpha-butylstyrene; Halogenated styrenes such as chlorostyrene and bromostyrene; And / or a vinyl group-containing styrene. In the case of a copolymer, examples of the comonomer copolymerizable with the styrene-based monomer include acrylonitrile, butadiene, alkyl acrylate, alkyl methacrylate, isobutylene, and / or isoprene.

Further, in the present invention, the styrenic polymer includes a waste styrene polymer (a waste polystyrene-based resin) that is discarded at an industrial site or at home. In one example, the styrenic polymer may be at least one selected from polystyrene (PS) and waste polystyrene (waste PS).

The first flame retardant is a flame retardant separated from the waste wire, and is not particularly limited as long as it has flame retardancy. The first flame retardant may vary depending on the type of the waste wire, but may be selected from, for example, a halogen compound, a phosphorus compound and / or an antimony compound, but is not limited thereto. In the present invention, the first flame retardant may be a flame retardant inorganic substance separated from a waste wire.

The first flame retardant may be included in the foamed particle according to the present invention in any one of the following formulas (a) to (c).

(a) dispersing in the interior of the flame-retardant polystyrene type expanded particles of the present invention

(b) The surface of the flame-retardant polystyrene type expanded particles of the present invention is partially coated or entirely coated

(c) dispersing the inside of the flame-retardant polystyrene type expanded particles of the present invention and coating the surface of the flame-retardant polystyrene type expanded particles of the present invention with a partial coating or a whole surface coating

Specifically, according to the first embodiment of the present invention, (a) the first flame retardant may be mixed with the styrene-based polymer and then foamed and dispersed in the foamed particle according to the present invention. According to a second embodiment of the present invention, (b) the first flame retardant may be included in the form of a partially coated (or entirely coated) particle surface after the foaming of the expanded particles according to the present invention is produced. According to a third embodiment of the present invention, (c) the first flame retardant is mixed with the styrenic polymer and then foamed and dispersed in the expanded particles according to the present invention, (Or entirely coated), dispersed in the expanded particles according to the present invention, and coated on the surface of the particles.

According to a preferred form, the first flame retardant preferably follows the second embodiment and the third embodiment. Specifically, it is preferable that the first flame retardant is included at least in the form of partially coating (or entirely coating) the surface of the expanded particles. In this case, the first flame retardant is partially coated (or entirely coated) on the surface of the expanded particles in direct contact with the flame, so that the flame retardancy is improved.

According to a more preferred embodiment, the first flame retardant may be in accordance with the second embodiment. Specifically, it is preferable that the first flame retardant is not dispersed in the inside of the expanded particles but is contained only in the form of partial coating (or front coating) on the surface of the expanded particles. In this case, since the first flame retardant is coated on the surface of the expanded particles in direct contact with the flame, the flame retardancy is improved. In addition, the same flame retardancy can be used as compared with the first embodiment, The coating amount of the first flame retardant is large, which is advantageous in the flame retardancy.

The second flame retardant is not particularly limited as long as it contains aluminum hydroxide (Al (OH) ₃ ) and sulfur (S). The second flame retardant is specifically selected from inorganic substances containing aluminum hydroxide (Al (OH) ₃ ) as a base component (main component) and sulfur (S) as a subcomponent. In one example, the second flame retardant may be selected from an inorganic powder mixed with a compound containing sulfur (S) and / or sulfur (S) and aluminum hydroxide (Al (OH) ₃ ). Aluminum hydroxide (Al (OH) ₃ ) contained in the second flame retardant agent generates moisture (H ₂ O) in the event of a fire, thereby suppressing ignition and heat generation. In addition, sulfur (S) contained in the second flame retardant agent reduces the concentration of oxygen around it, thereby suppressing the progress of combustion and reducing the generation of smoke and the like, thereby achieving excellent flame retardancy.

The second flame retardant may be selected, for example, from a zeolite spent catalyst. The zeolite spent catalyst is an industrially discarded zeolite-based catalyst, and is not particularly limited as long as it contains aluminum hydroxide (Al (OH) ₃ ) and sulfur (S). Also, according to one embodiment, the zeolite spent catalyst may be selected from those which have been discarded in a pyrolysis process of petroleum and the like.

The second flame retardant may be included in the expanded particles according to the present invention in the same manner as the first flame retardant. Specifically, the second flame retardant may be mixed with the styrenic polymer and then foamed and dispersed in the foamed particles according to the present invention. The second flame retardant may be included in the form of a partially coated (or entirely coated) particle surface after the expanded particles of the present invention are foamed. In addition, the second flame retardant is mixed with the styrenic polymer and then foamed to be dispersed in the expanded particles according to the present invention, and then partially coated (or entirely coated) on the surface of the particles after the foam is produced. And may be contained in the form of a coating on the surface of the particles as well as inside the expanded particles. In one example, the second flame retardant may be dispersed in the foamed particles according to the present invention.

Further, according to a preferred embodiment of the present invention, the expanded particles according to the present invention may further comprise a third flame retardant. In this case, the third flame retardant agent is selected from organic substances having an acetamido group (CH ₃ CO-). Such a third flame retardant is included in the form of a partial coating (or a front coating) on the surface of the expanded particles according to the present invention. According to an exemplary embodiment, the third flame retardant may be mixed with the first flame retardant and / or the second flame retardant and then partially coated (or entirely coated) on the surface of the expanded particles according to the present invention. According to the present invention, the third flame retardant selected from an organic substance having an acetyl group (CH ₃ CO-) improves the flame retardancy and improves the bonding force (fusion property) between the expanded particles.

According to a preferred embodiment of the present invention, the second flame retardant is dispersed inside the expanded particles of the present invention, and the first and third flame retardants are partially coated (or entirely coated) on the surface of the expanded particles of the present invention . Specifically, the expanded particles according to the present invention comprise a foamed particle main body containing a styrene polymer as a main component and a flame retardant coating layer coated on the surface of the foamed particle main body, wherein the foamed particle main body is dispersed and mixed And the flame retarding coating layer has a structure comprising a first flame retardant as an inorganic material and a third flame retardant as an organic material. At this time, the flame retardant coating layer is formed by coating a surface of the foamed particle body with a spray coating and / or impregnation coating such that a flame retardant coating liquid containing a first flame retardant (inorganic material), a third flame retardant (organic material) and an organic solvent .

Further, according to an exemplary embodiment, the flame retardant coating layer may further include a plasticizer. Specifically, the flame retarding coating layer may be formed by spraying (spraying) coating and / or impregnating coating onto the surface of the foamed particle body, wherein the flame retarding coating solution comprises a first flame retardant (inorganic substance), a third flame retardant (organic substance), a plasticizer and an organic solvent Coating method.

The above-described expanded particles according to the present invention can be usefully used for, for example, insulation. Specifically, the expanded particles according to the present invention may be molded into a predetermined shape, for example, a panel or a bar shape, and may be usefully used as a heat insulation material of a building. Further, the expanded particles according to the present invention can be foamed by a foaming process as usual, and the foaming process is not limited. The expanded particles according to the present invention can be foamed by physical and / or chemical means, and can be foamed, for example, by heating and / or steam. In addition, the foaming step may be performed once or twice or more.

Hereinafter, a method for producing flame-retardant polystyrene-based expanded particles according to the present invention (hereinafter abbreviated as "method for producing expanded particles") will be described. Hereinafter, a method for producing expanded particles according to the present invention will be described, and specific embodiments of expanded particles according to the present invention will be described together with explanations of exemplary embodiments thereof.

First Embodiment

The method for producing expanded particles according to the first embodiment of the present invention comprises the steps of: (S1-1) separating a first flame retardant from a waste wire; (S1-2) obtaining polystyrene-based expanded particles from a mixture containing a styrene-based polymer and a second flame retardant; And (S1-3) coating a surface of the polystyrene-based expanded particle with a first flame retardant separated from the waste wire. Each step will be described as follows.

(S1-1): separation of the first flame retardant from the waste wire

The present invention recycles waste wires that are discarded in industry and / or the home. In the present invention, the waste wire to be recycled is not particularly limited, and is collectively referred to as a general cable and a communication cable used for communication. The waste wire may be any as long as it contains a flame retardant. According to the present invention, the flame retardant is separated and recovered from the waste wire and used as the first flame retardant of the present invention. At this time, the separated and recovered recovered material may include at least a first flame retardant, and besides the first flame retardant, adducts such as an organic solvent used in the separation process may be further mixed.

Generally, the waste wire has at least one metal wire (mainly copper wire) and a sheath (covering material) for protecting the metal wire. At this time, most of the envelope (covering material) constituting the waste wire includes a resin (polymer) and a flame retardant. (PE), polypropylene (PP), polyurethane (PU) and / or epoxy resin, etc., which constitute the casing of the waste wire, although it may vary depending on the kind of the waste wire. And in most cases, polyvinyl chloride (hereinafter abbreviated as "PVC" in some cases).

The flame retardant constituting the outer surface of the waste wire is mainly an inorganic flame retardant having a flame retarding effect of grade 2 or higher, and is made of an inorganic flame retardant such as a halogen-based compound, a phosphorus-based compound, and / or an antimony-based compound.

According to the present invention, the resin and the first flame retardant are separated from the waste wire. In the present invention, the first flame retardant is included in the waste wire, and this specifically means the above-mentioned inorganic flame retardant constituting the envelope of the waste wire. The process of separating the resin from the waste wire and the first flame retardant is not particularly limited, and it can be separated, for example, by a process such as cutting, cutting, pressing, heating and / or dissolving the waste wire. At this time, the separation step of the first flame retardant may include at least a dissolution step using, for example, an organic solvent.

According to one embodiment, step (S1-1) of separating the first flame retardant from the waste wire may comprise a dissolution process and a precipitation separation process. An embodiment of each process will be described below.

[1] Dissolution Process

Waste wire and organic solvent are put into the dissolution tank to dissolve the outer skin. By this dissolution, the sheath (covering material) constituting the waste wire is separated. That is, the coating mixture containing the resin of the waste wire and the first flame retardant is separated by dissolution. At this time, the waste wire can be cut into a predetermined size, and / or pulverized to a size of about 20 탆 to 5 mm, and then put into a dissolution tank. Further, the cut and / or pulverized waste wires can be squeezed through the pressure roller and then put into the dissolution tank. When the waste wire is put into a dissolving tank, the contact area with the organic solvent is enlarged and the solubility can be improved when the waste wire is put into the dissolution tank after cutting, grinding and / or squeezing as described above.

 In addition, the dissolution may proceed at room temperature or while heating. Specifically, the waste wire and the organic solvent may be put into a dissolution tank and then dissolved at room temperature, or dissolved in the dissolution tank while being heated. In the present invention, the room temperature may vary depending on the season, but it may range, for example, from -5 ° C to 30 ° C. In the case of dissolving while heating, for example, the organic solvent can be dissolved while maintaining the temperature at 25 to 150 ° C. At this time, if the temperature is less than 25 占 폚, the effect of improving the dissolution depending on the application of heat may be insignificant. If the temperature exceeds 150 ° C, for example, the volatilization amount of the organic solvent may become large. The method of applying heat is not particularly limited, and for example, heat can be applied to the inner wall surface and / or the outer wall surface of the melting tank by providing a heat supply means such as a heating coil.

In the present invention, the organic solvent is not limited as long as it can dissolve the resin (e.g., PVC, etc.) constituting the envelope of the waste wire. The organic solvent may be selected from, for example, a hydrocarbon-based organic solvent. The organic solvent may vary depending on the kind of the resin constituting the shell, but it may be a mixture of acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK) Ketones such as butyl methyl ketone (BMK); Ethers such as tetrahydrofuran (THF); Alcohols such as methanol, ethanol and butanol; And / or aromatic solvents such as benzene, toluene and xylene, and the like can be used.

The organic solvent is preferably selected from water-soluble organic solvents having a higher solubility in water than resins (e.g., PVC, etc.) constituting the waste wires. The organic solvent may be at least one ketone selected from, for example, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK) and butyl methyl ketone It is good to do. According to the present invention, when the organic solvent is water-soluble (e.g., ketone) having a higher solubility in water than the resin constituting the waste wire, it is preferable to use a resin (e.g., PVC) and a first flame retardant Separation, and / or separation and recovery of the organic solvent are easy, and will be described later.

In addition, the water-soluble organic solvent having higher solubility in water than the resin constituting the waste wire (for example, PVC, etc.) is used. However, depending on the type of the organic solvent, the organic solvent may be heated to a temperature of 55 to 130 ° C It is good to dissolve. Preferably, the organic solvent is dissolved by heating at the boiling point (± 5 ° C of boiling point) of the organic solvent. Specifically, when the boiling point of the organic solvent is T _b 캜, it is preferable to heat and dissolve the organic solvent at T _b 캜 5 캜. When heated at such a temperature, it is possible to have a low volatilization amount with high solubility.

Through the dissolving process as described above, the coating mixture containing the resin and the first flame retardant is separated from the waste wire. At this time, the coating mixture may be discharged to the lower end of the dissolution tank to be separated and recovered. The metal wire remaining in the melting tank can be taken out separately and recovered. Further, the coating mixture separated through the present dissolution step may be a liquid or gel phase including a resin, a first flame retardant, and an organic solvent. In one example, the coating mixture may comprise a resin (e.g., PVC), a first flame retardant, and an organic solvent in a weight ratio of 0.5: 40: 0.1-30: 10-150, more specifically, , PVC), a first flame retardant, and an organic solvent in a weight ratio of 5 to 30: 0.5 to 20: 30 to 120.

[2] Precipitation separation process

Next, the first flame retardant is separated from the coating mixture. That is, the resin and the first flame retardant are separated from the mixture of the resin and the first flame retardant. The case where the resin constituting the waste wire is not separated and used as the material of the expanded particles according to the present invention may be considered, but in this case, the toxic gas can be discharged. Specifically, most of the waste wires contain polyvinyl chloride (PVC) as a resin constituting the shell, and such polyvinyl chloride (PVC) can discharge toxic gases such as dioxin when burned. Thus, the resin (e.g., PVC) and the first flame retardant are separated from the coating mixture, respectively, and the separated first flame retardant is used for the flame retardancy of the expanded particles according to the present invention. And the separated resin (eg, PVC) can be reused as a separate use.

At this time, the separation of the first flame retardant from the coating mixture is carried out by precipitation through the difference in specific gravity. For example, the coating mixture is allowed to stand in the dissolution tank for a predetermined time to allow the first flame retardant (inorganic particles) having a large specific gravity to precipitate to the lower end of the dissolution tank, thereby separating and recovering the first flame retardant from the coating mixture. At this time, a small amount of solvent may remain in the recovered first flame retardant, which may be completely removed through volatilization and / or drying, etc., by heating or the like to recover only the pure first flame retardant.

According to a preferred embodiment of the present invention, it is preferable to separate the first flame retardant after further adding water to the coating mixture. Specifically, in the present precipitation separation step, water is further added to the coating mixture so that the resin floats up to the upper layer, and the first flame retardant is allowed to settle; And a resin from the coating mixture; A mixed solution containing an organic solvent and water; And a second step of separating the first flame retardant from each other.

As described above, the coating mixture obtained in the dissolution step contains a resin solution (a liquid or a gel phase in which the resin is dissolved in an organic solvent) containing an organic solvent and a resin, and a first flame retardant (inorganic particle) Is precipitated. At this time, according to a preferred embodiment of the present invention, when water is added to the coating mixture as described above, a resin (e.g., PVC) having a low solubility in water is aggregated and changed into a solid phase.

Specifically, when water is added to the coating mixture containing water which is more soluble in water than the resin constituting the waste wire as the organic solvent, the solubility in the organic solvent is diluted due to the addition of water The solubility of the resin decreases. At this time, the resin is aggregated and becomes a solid phase. The solidified resin has a low specific gravity and floats on the upper layer. Therefore, when water is added to the coating mixture, the resin coalesces to become a solid phase, and the resin is floated up to the upper layer due to the difference in specific gravity, and the first flame retardant (inorganic particles) having a large specific gravity is precipitated downward. As described above, the resin floated on the upper layer can be easily separated and recovered through filtration or the like.

Further, according to an exemplary embodiment of the present invention, the precipitation separation process can be implemented in a corn-type separation tank. Specifically, a tapered separator in the form of a corn may be used. At this time, the end of the corn has a diameter capable of filtering the solid phase resin. Further, a filter (filter net) may be installed on the lower side of the separation tank. When the coating mixture is introduced into the separating tank, the solution (organic solvent + water) and the precipitated first flame retardant are simultaneously discharged to the bottom of the separator, and the precipitated first flame retardant is recovered by filtration through a filter. The resin in the solid phase is trapped in the separating tank at the corn end, and is easily recovered.

The first flame retardant separated and recovered as described above may be used in the following step (S1-3) after having the average size of 0.1 to 200 mu m through, for example, pulverization. At this time, if the size of the first flame retardant is out of the above range and is too small or large, it may not be preferable in terms of dispersibility, coating property and flame retardancy.

Accordingly, in the case of separating the resin and the first flame retardant from the waste wire through dissolution, and then separating the resin and the first flame retardant through precipitation separation, when water is further added to the coating mixture to separate the resin, Of course, it is very easy and economical to separate and recover the organic solvent. Specifically, in separating the resin from the coating mixture, the resin can be easily separated and recovered by a method such as coagulation and filtration which is advantageous in terms of cost and process without using fractional distillation or the like.

In addition, the present invention may further include a step of separating the organic solvent from the mixed solution. Specifically, in this precipitation separation step, water is added to the coating mixture as described above (first step), and then a mixture solution containing the resin floating as an upper layer, an organic solvent and water, and a first flame retardant The organic solvent can be separated and recovered separately from the mixed solution containing the organic solvent and water separated and recovered in the second step. The organic solvent can be separated and recovered, for example, by fractional distillation. And the recovered organic solvent can be reused in the dissolving process.

On the other hand, in the case of using fractional distillation, it is advantageous in that the separation of water and organic solvent is simpler and faster than the separation of resin and organic solvent, and the cost due to the use of thermal energy. And the recovery rate of the organic solvent is high. Therefore, when water is added to the coating mixture obtained in the above-mentioned dissolution step, separation and economical efficiency can be achieved more efficiently than when water is not added.

In addition, when water is added to the coating mixture, 20 to 85 parts by weight of water may be added to 100 parts by weight of the resin. If the content of water to the resin is less than 20 parts by weight, unreacted resin may remain. If the content of water exceeds 85 parts by weight, the synergistic effect upon excessive use is not so large. Considering this point, it is preferable to add 50 to 85 parts by weight of water to 100 parts by weight of the resin. At this time, when 50 parts by weight or more of water is added, for example, a resin recovery rate of 95% or more can be achieved.

(S1-2) Step: Production of polystyrene-based expanded particles

The step (S1-2) is not particularly limited as long as it can obtain polystyrene-based expanded particles from a mixture (polystyrene-based composition) containing a styrene polymer and a second flame retardant. The styrene type polymer is as described above. The mixture (polystyrene composition) is prepared as usual, but is not particularly limited as long as it contains the second flame retardant specified in the present invention.

The above mixture (polystyrene-based composition) may contain a commonly used foaming agent (e.g., pentane) and a dispersant (e.g., tricalcium phosphate) and the like, while using a styrene polymer as a main component. And the mixture further comprises a second flame retardant specified in the present invention. Further, the mixture may further contain, as an additive, a bubble controlling agent and / or a foaming power modifier and the like. The method for producing the polystyrene-based expanded particles from such a mixture is not particularly limited, and can be carried out in the same manner as usual.

The second flame retardant is not particularly limited as long as it contains aluminum hydroxide (Al (OH) ₃ ) and sulfur (S) as described above. The second flame retardant may be selected, for example, from a zeolite spent catalyst. In the present invention, the zeolite spent catalyst is a zeolite-based catalyst that has been used in an industrial industry such as chemical industry and has been discarded. This zeolite catalyst is composed of aluminum hydroxide (Al (OH) ₃ ) Is not particularly limited.

According to an exemplary embodiment of the present invention, the zeolite spent catalyst may be selected from the FCC spent catalyst used in a cracking process or the like. In the present invention, the FCC spent catalyst is not limited as long as it is a spent catalyst that has been used in Fluidized Catalytic Cracking (FCC) and contains aluminum hydroxide (Al (OH) ₃ ) and sulfur (S) . Generally, FCC catalysts are used as cracking catalysts in most cracking processes, such as petroleum refining processes and gas cracking processes. The FCC catalyst is porous, which is representative of a zeolitic porous body containing aluminum hydroxide (Al (OH) ₃ ).

In the present invention, the waste catalyst of the FCC is a waste catalyst which is used and discarded in a pyrolysis process such as a petroleum refining process, which is selected from those containing aluminum hydroxide (Al (OH) ₃ ) and sulfur (S). At this time, aluminum hydroxide (Al (OH) ₃ ) is a component derived from the raw material of the FCC catalyst, and sulfur (S) is introduced separately. Sulfur (S) can be introduced artificially into the FCC catalyst, for example through adsorption. According to one embodiment, the FCC spent catalyst may be a spent zeolite-based FCC spent catalyst that has been used up in a pyrolysis process (refinery process) of petroleum. At this time, in the petroleum refining process, sulfur component is generated from the crude oil during pyrolysis, and this sulfur component is adsorbed on the FCC catalyst. Therefore, the FCC waste catalyst discarded in the pyrolysis process of petroleum contains aluminum hydroxide (Al (OH) ₃ ) derived from a raw material thereof and sulfur (S) adsorbed in a pyrolysis process and can be usefully used in the present invention .

Further, in the case of using the FCC waste catalyst that is discarded in the pyrolysis process of petroleum as the second flame retardant, it is preferable to use it after cleaning through a cleaning solvent. For example, oil fractions such as heavy oil and light oil may remain in the FCC waste catalyst used in the process of pyrolyzing heavy oil with light oil, and such oil may adversely affect flame retardancy. Accordingly, it is preferable that the oil is removed by washing. In the present invention, the washing is not particularly limited as long as it can remove the oil (for example, heavy oil or light oil) remaining in the FCC closure, and this can be selected, for example, from a washing process with a washing solvent. At this time, the cleaning solvent is not particularly limited as long as it is capable of washing oil (for example, heavy oil or light oil), and may be selected from alkane hydrocarbons having 6 or more carbon atoms, for example. Specific examples of the cleaning solvent include, but are not limited to, alkane hydrocarbons such as n-hexane and / or n-heptane.

The above-mentioned second flame retardant is mixed and dispersed to obtain a foamable mixture (polystyrene-based composition) for the production of expanded particles according to the present invention.

According to an exemplary embodiment of the present invention, the second flame retardant (e.g., zeolite waste catalyst) may be pulverized through a ball mill or the like to a size of 1 to 200 mesh, For example, 5 to 150 mesh. In the case of pulverizing to such a size, it can be uniformly dispersed and mixed in a foamable mixture (polystyrene-based composition), and can also be effective in improving flame retardancy.

In addition, the foamable mixture (polystyrene composition) may contain the styrene polymer and the second flame retardant in a weight ratio of 5: 0.1-5. If the amount of the second flame retardant is less than the above range, the effect of improving the flame retardancy may be insignificant depending on the use thereof. If the amount is larger than the above range, it may be undesirable in terms of ductility and brittleness of the final product. Considering this point, it is preferable that the foamable mixture (polystyrene composition) contains the styrene polymer and the second flame retardant in a weight ratio of 5: 1 to 3: That is, it is preferable that the expanded particles according to the present invention contain the styrene polymer and the second flame retardant (e.g., zeolite waste catalyst) at a weight ratio of 5: 1 to 3.

The foamable mixture (polystyrene-based composition) may be molded into particles such as beads and then foamed or foamed while being molded into a particle shape. In the present invention, the foaming includes physical and / or chemical foaming, which can proceed, for example, to a process as usual. For example, it can be made into expanded particles having a proper foaming structure by heating foamed with a chemical foaming agent (e.g., pentane, etc.) or by steam at high pressure / high temperature conditions as usual.

(S1-3) Step: Coating of the first flame retardant

The surface of the thus obtained expanded particles is coated with the first flame retardant separated from the waste wire. The coating method is not particularly limited, but may be selected from, for example, spray coating and / or impregnation coating. At this time, the first flame retardant may be mixed with an organic solvent and coated.

The organic solvent may be selected from the hydrocarbon-based organic solvents listed above. Specific examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK) and butyl methyl ketone (BMK); Ethers such as tetrahydrofuran (THF); Alcohols such as methanol, ethanol and butanol; And / or aromatic solvents such as benzene, toluene and xylene, and the like can be used.

Further, when the first flame retardant is coated, an organic binder may be further used to improve the adhesion. Specifically, a flame retardant coating liquid containing a first flame retardant, an organic binder and an organic solvent is prepared and coated on the surface of the expanded particles, followed by curing (drying) to form a first flame retardant Coating. When the organic binder is further mixed and used as described above, it may be advantageous not only to improve the adhesion of the first flame retardant but also to improve the bonding force (fusion-bonding property) between the expanded particles.

The organic binder is not limited as long as it has adhesiveness. The organic binder may be selected from, for example, a styrene-based polymer, an acrylic resin, a polyurethane and / or an epoxy resin. The flame retardant coating liquid may contain 5 to 60% by weight of the first flame retardant and 2 to 30% by weight of the organic binder based on the total weight of the flame retardant coating liquid, and the remaining amount may be composed of an organic solvent.

Hereinafter, a method for producing expanded particles according to a second embodiment of the present invention will be described. In describing the second embodiment of the present invention, terms used in the same manner as the manufacturing method of the first embodiment have the same functions, and a detailed description thereof will be omitted. In addition, if there is a part which is not specifically described below, this is the same as the first embodiment. In addition, as occasion demands, the first embodiment may include the configuration of the second embodiment described below. That is, if there is a part which is not described in the first embodiment, it is as described in the second embodiment.

Second Embodiment

A method for producing expanded particles according to a second embodiment of the present invention comprises the steps of: (S2-1) separating a first flame retardant from a waste wire; (S2-2) obtaining polystyrene-based expanded particles from a mixture containing a styrene polymer and a second flame retardant; (S2-3) obtaining a flame retardant coating liquid comprising a third flame retardant and a first flame retardant separated from the waste wire; And (S2-4) coating the flame-retardant coating solution on the surface of the polystyrene-based expanded particles. Each step will be described as follows.

(S2-1) Step: Separation of the first flame retardant from the waste wire

The step (S2-1) of the second embodiment is not particularly limited if it includes a step of separating the first flame retardant from the waste wire. The step S2-1 is the same as the step S1-1 of the first embodiment, and a detailed description thereof will be omitted.

(S2-2) Step: Production of polystyrene-based expanded particles

The step (S2-2) of the second embodiment is not particularly limited as long as it can obtain polystyrene-based expanded particles from a mixture (polystyrene-based composition) comprising a styrene polymer and a second flame retardant. The step S2-2 is the same as the step S1-2 of the first embodiment, and a detailed description thereof will be omitted.

(S2-3) Step: Preparation of flame retardant coating liquid

A flame retardant coating liquid containing the third flame retardant and the first flame retardant is obtained. Specifically, the flame retardant coating liquid includes a third flame retardant specified in the present invention and a first flame retardant separated from the waste wire. At this time, the flame retardant coating liquid may further include an organic solvent. Specifically, the flame retardant coating liquid may include a third flame retardant, a first flame retardant, and an organic solvent.

At this time, the organic solvent is a hydrocarbon-based solvent, which can be selected from those exemplified above. The organic solvent includes, for example, ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK) and butyl methyl ketone (BMK); Ethers such as tetrahydrofuran (THF); Alcohols such as methanol, ethanol and butanol; And / or aromatic solvents such as benzene, toluene and xylene, and the like can be used.

In the present invention, the third flame retardant is an organic material, which is selected from organic materials having at least one acetic group (CH ₃ CO-) in the molecule. According to the present invention, such a third flame retardant (organic material) achieves flame retardancy in comparison with other organic materials. That is, the acetyl group (CH ₃ CO-) of the third flame retardant has a property of not sticking to fire. Further, the third flame retardant (organic material) improves the bonding force (fusion property) between the expanded particles. Accordingly, the third flame retardant having an acetyl group (CH ₃ CO-) is more advantageous in flame retardancy than other organic binders, and also improves the bonding force (fusion property) between expanded particles and improves mechanical properties such as tensile strength.

In the present invention, the third flame retardant is not particularly limited as far as it has an acetic group (CH ₃ CO-). The third flame retardant may be at least one selected from cellulose acetate and cellulose triacetate, and they are biodegradable in addition to flame retardance, which is preferable from the viewpoint of environmental friendliness.

The flame retardant coating liquid may include the third flame retardant, the first flame retardant, and the organic solvent as described above, and may contain 2 to 30% by weight of the third flame retardant and 5 to 60% by weight of the first flame retardant based on the total weight of the flame retardant coating liquid. The remaining amount is organic solvent. If the content of the third flame retardant is less than 2% by weight, the effect of improving the flame retardancy and the bonding strength (fusion property) of the flame retardant may be insignificant. If the content of the third flame retardant is more than 30% Which may be undesirable. If the content of the first flame retardant is less than 5% by weight, the effect of improving the flame retardancy may be insignificant. When the content of the first flame retardant exceeds 60% by weight, the dispersibility and coating properties may be undesirable. The first flame retardant is an inorganic flame retardant separated from the waste wire, which may have an average size of 0.1 to 200 mu m as described above.

According to a preferred embodiment, the flame retardant coating liquid may further include a plasticizer. Specifically, the flame retardant coating liquid may include a third flame retardant, a first flame retardant, a plasticizer, and an organic solvent. By the addition of such a plasticizer, for example, the moldability can be improved in molding into a product, and the glass transition temperature of the third flame retardant such as cellulose acetate is lowered, and even at a low temperature (for example, 130 ° C to 150 ° C) The foaming particles can be bonded (low temperature bonding) with a good bonding force (fusion bonding property).

The plasticizer is not particularly limited as long as it can improve the thermoplasticity of the third flame retardant. The plasticizer may be selected from, for example, a phthalate-based compound, and specific examples thereof include dimethyl phthalate (DMP), dibutyl phthalate (DBP) and / or dioctyl phthalate (DOP) And the like.

The plasticizer may be contained in an amount of, for example, 0.5 to 10% by weight based on the total weight of the flame retardant coating liquid. In one example, the flame retardant coating solution further comprises a plasticizer, which may comprise from 2 to 30% by weight of the third flame retardant, from 5 to 60% by weight of the first flame retardant, and from 0.5 to 10% by weight of the plasticizer, based on the total weight of the flame retardant coating solution . The remaining amount is organic solvent. At this time, if the content of the plasticizer is less than 0.5% by weight, the effect of improving the moldability and the low-temperature bonding property upon addition thereof may be insignificant. When the plasticizer content is more than 10% by weight, the synergistic effect with excessive use is not so large. In some cases, for example, the flowability of the flame retardant coating liquid becomes too high and the coating workability and / And the like can be lowered.

(S2-4) Step: coating of flame retardant coating liquid

The obtained flame retarding coating liquid is coated on the surface of the expanded particles obtained in the step (S2-2). The coating method is not particularly limited. For example, by spray coating and / or impregnation coating. And can be dried (cured) after coating. The drying may be selected from, for example, natural drying, hot air drying, infrared (IR) drying and / or ultraviolet (UV) drying.

On the other hand, the molded article according to the present invention is not limited as long as it includes the expanded particles of the present invention as described above. The molded article according to the present invention includes the expanded particles of the present invention as described above, and may have, for example, a panel shape, a bar shape, or the like, or may have a three-dimensional shape.

According to one embodiment, the method of manufacturing a molded article according to the present invention may include a step of putting the expanded particles of the present invention into a molding machine, and then molding the molded body while applying steam or heat. At this time, the molding machine may include a mold to have a shape such as a panel or a bar. By this molding, the expanded particles can be foamed by steam or heat while being molded into a molded body having a predetermined shape. At this time, conditions such as temperature and pressure of steam at the time of molding can be proceeded as usual.

According to a preferred embodiment, the method for manufacturing a molded article according to the present invention may further include a step of coating an organic solvent on the expanded particles before applying the steam or heat. The coating process of the organic solvent may be performed only before the application of steam or heat. Specifically, the coating process may be carried out before the expanded particles are introduced into the molding machine or after the expanded particles are introduced into the molding machine. Thereafter, steam or heat is applied so that predetermined foaming proceeds simultaneously with molding. At this time, the above-mentioned foamed particles are coated with the third flame retardant, and the organic solvent is selected from organic solvents capable of dissolving both the styrene polymer and the third flame retardant constituting the expanded particles. According to this, not only the bonding strength between the third flame retardants, but also the bonding strength between the third flame retardant and the styrene polymer is improved and the physical properties of the molded article are effectively improved.

Specifically, in the case of using cellulose acetate as the third flame retardant, for example, before the expanded particles are put into a molding machine, or after the expanded particles are put into a molding machine, an organic solvent (a styrene polymer and cellulose acetate When steam or heat is applied, a predetermined amount of styrene polymer and cellulose acetate are melted on the surface of the expanded particles, and cellulose acetate is mutually molten, and cellulose acetate and styrene polymer And are also melt-bonded to each other. As a result, not only the foamed particles but also the foamed particle body and the material constituting the surface thereof are mutually penetrated (impregnated) and have an excellent bonding force, which improves the mechanical properties of the formed body.

The organic solvent is not particularly limited as long as it can dissolve the styrene polymer and the third flame retardant (e.g., cellulose acetate). Examples thereof include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) Ketones such as diisobutyl ketone (DIBK) and / or butyl methyl ketone (BMK); And / or ethers such as tetrahydrofuran (THF) and the like. Such an organic solvent may be coated on a molded article by, for example, spray coating and / or impregnation coating, and may be dried by hot air drying or natural drying.

According to the present invention described above, it has excellent flame retardancy and high economical efficiency. First, it has excellent flame retardancy by the first flame retardant (flame retarding effect of grade 2 or higher) separated from the waste wire.

In addition, the flame retardancy is effectively improved by the second flame retardant (e.g., zeolite spent catalyst, etc.). Specifically, in a fire, aluminum hydroxide (Al (OH) ₃ ) contained in the second flame retardant generates moisture (H ₂ O) to suppress ignition and heat generation. More specifically, when a fire occurs, and the second is the aluminum hydroxide (Al (OH) ₃₎ contained in the flame retardant pyrolysis water (H ₂ O) to produce [2Al (OH) ₃ + heat -> Al ₂ O ₃ + 3H ₂ O]. At this time, the generated moisture (H ₂ O) suppresses ignition, induces an endotherm in the early stage of fire, and lowers the ambient temperature to prevent spread of fire. At the same time, the sulfur (S) contained in the second flame retardant is desorbed when a fire occurs, and the concentration of the ignition-providing element such as oxygen or hydrogen is reduced [S + O ₂ -> SO _x ] . In addition, sulfur (S) reduces the concentration of the combustion gas generated in the event of fire, thereby suppressing the generation of smoke, thereby achieving excellent flame retardancy.

In addition, according to the present invention, wastes such as waste wires and waste catalysts are used as the first and second flame retardants, which is highly economical. Further, the second flame retardant is selected from an inorganic substance such as a zeolite waste catalyst to improve the mechanical strength and the like.

In addition, according to the present invention, when the third flame retardant selected from an organic substance having an acetyl group (CH ₃ CO-) is coated, the flame retardancy is improved and the bonding force (fusion property) between the expanded particles is improved.

Further, according to the present invention, the separation step of separating the resin and the first flame retardant from the waste wire is improved, and the resin constituting the waste wire as well as the flame retardant can be efficiently recycled. Particularly, in separating the resin and the first flame retardant from the waste wire, a water-soluble organic solvent having a higher solubility in water than the resin constituting the waste wire is used in the dissolution step. In the precipitation separation step, 1 flame retardant) is separated and separated, the resin is coalesced to become a solid phase and floated to the upper layer. The first flame retardant having a large specific gravity is precipitated downward, and the resin and the first flame retardant , Respectively.

Hereinafter, examples and comparative examples of the present invention will be exemplified. The following examples are provided to illustrate the present invention in order to facilitate understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. In addition, the following comparative example is not meant to be a prior art, but is provided for comparison with an embodiment only.

[Example 1]

≪ Separation of first flame retardant &

A waste wire (home TV cable) using PVC and a secondary flame retardant (phosphorus flame retardant) was prepared. Thereafter, the waste wire was cut into a length of about 5 cm in the dissolution tank, and then water-soluble methyl ethyl ketone (MEK) was added as an organic solvent. The temperature in the melting bath was maintained at about 80 캜 and dissolved for 1 hour. Next, the copper wire was removed by filtration, and the filtrate (coating mixture) was recovered and put into a separating tank of a separate corn type. At this time, the filtrate (coating mixture) includes PVC, a first flame retardant (phosphorus flame retardant) and an organic solvent (MEK).

Thereafter, water was added to the separation vessel, and then left at room temperature (about 15 ° C) for about 30 minutes. After water was added, it was left to stand for a predetermined time. As a result, it was found that the PVC solidified by association (coagulation) and floated to the upper layer. Next, the solution containing the first flame retardant, the organic solvent (MEK) and water was discharged to the lower end of the separation tank, and then the first flame retardant was separated and recovered through the sieve. The recovered first flame retardant was dried and pulverized to have an average size of about 12 μm using a ball mill.

<Preparation of expanded particles>

Water and a dispersant (tricalcium phosphate) were added to the reactor and stirred, and then polystyrene (PS) and a second flame retardant were mixed. Thereafter, the foamed polystyrene (EPS) particles were prepared by raising the temperature to about 125 캜 according to a conventional process, introducing the foaming agent (pentane) under a nitrogen pressure, and maintaining the pressure at a predetermined pressure.

At this time, the second flame retardant is an inorganic material containing aluminum hydroxide (Al (OH) ₃ ) and sulfur (S), and after purchasing an FCC spent catalyst (zeolite spent catalyst) used in the process of pyrolyzing heavy oil with light oil, This was washed several times with n-hexane and then with an average size of about 120 mesh through ball milling and sieving. In addition, the reactor was used so that the weight ratio of polystyrene (PS) and the second flame retardant was 5: 1.

&Lt; Coating of the First Flame Retardant &

A flame retardant coating solution (25% by weight of a first flame retardant) prepared by dispersing the first flame retardant in methyl ethyl ketone (MEK) was prepared, spray coated on the surface of the expanded polystyrene (EPS) particles and dried.

<Molding>

Next, expanded polystyrene (EPS) particles coated with the first flame retardant were put into a molding machine to seal the mold, and then hot steam was injected into the molding machine to produce a panel-shaped expanded polystyrene (EPS) specimen .

[Example 2]

Except that the organic solvent used in the separation of the first flame retardant from the waste wire and the flame retardant coating liquid used in the coating of the first flame retardant on the surface of expanded polystyrene (EPS) particles .

Specifically, the first flame retardant was separated from the waste wire by dissolving acetone (Acetone) as an organic solvent at the time of dissolution and maintaining the temperature in the dissolution tank at about 60 ° C to dissolve the first flame retardant. .

Further, in coating the first flame retardant on the surface of expanded polystyrene (EPS) particles, a flame retardant coating solution obtained by further mixing a third flame retardant and a plasticizer was used. Specifically, a flame retardant coating liquid containing 25% by weight of a first flame retardant, 5% by weight of a third flame retardant, 2% by weight of a plasticizer and a residual methyl ethyl ketone (MEK) was prepared and sprayed onto the surface of expanded polystyrene (EPS) specimen was prepared in the same manner as in Example 1, except that the epoxy resin composition was spray-coated and dried to prepare a panel-shaped expanded polystyrene (EPS) specimen. At this time, cellulose acetate was used as the third flame retardant, and dimethyl phthalate (DMP) was used as the plasticizer.

[Comparative Example 1]

The same procedure as in Example 1 was carried out except that a general zeolite catalyst was used instead of the FCC spent catalyst as the second flame retardant. Specifically, a panel-shaped expanded polystyrene (EPS) specimen was prepared in the same manner as in Example 1, except that a zeolite catalyst containing no sulfur (S) was used as the second flame retardant.

[Comparative Example 2]

A foamed polystyrene (EPS) specimen in the form of a panel was prepared in the same manner as in Example 1, except that the second flame retardant was not mixed.

[Comparative Example 3]

A panel-shaped expanded polystyrene (EPS) specimen was prepared in the same manner as in Example 1, except that the first flame retardant separated from the waste wire was not coated.

The EPS specimens (molded products) according to each of the Examples and Comparative Examples were evaluated for flame retardancy and tensile strength as follows. The results are shown in Table 1 below.

&Lt; Evaluation of flame retardancy &

First, EPS specimens (molded products) according to each of the examples and comparative examples were placed in a sealable chamber, each specimen was ignited for 10 seconds through an igniter (torch), and then the concentration of carbon dioxide (CO ₂ ) , Pressure and temperature changes (ΔT) were measured. At this time, the temperature change? T is a value obtained by subtracting the temperature before ignition (initial) from the temperature after ignition (after 10 seconds). Further, after the igniter (torch) was removed, the flame existence time was measured.

&Lt; Evaluation of tensile strength &

In order to investigate the bonding strength between foamed particles of EPS specimens (molded products), each EPS specimen (molded product) was cut into a rod shape and tensile strength (N / cm ² ) was measured using a tensile strength tester.

            <Evaluation results of flame retardancy and tensile strength> Remarks CO ₂ concentration
(ppm) Chamber pressure
(mmHg) Temperature change
(? T)  Flame Presence Time (seconds) The tensile strength
(N / cm ² ) Example 1 1,131 1,075 15 ℃ Disappear with torch removal 19 Example 2 1,107 1,042 14 ℃ Disappear with torch removal 26 Comparative Example 1
1,340 1,453 24.1 DEG C 5 seconds 18 Comparative Example 2
1,547 1,604 26.4 DEG C 15 seconds 21 Comparative Example 3
1,182 1,518 29.3 DEG C 8 seconds 20

1. Example - Comparison of Comparative Example 1

In the case of Comparative Example 1, since sulfur (S) is not present, the reaction is sufficiently carried out with oxygen in the chamber, and the CO ₂ concentration is evaluated to be higher than that in the embodiment. Also, when the pressures in the chamber are compared, in Comparative Example 1, the amount of combustion gas is large and the pressure is evaluated to be high. It is considered that in the case of Comparative Example 1, the total combustion gas production amount due to the continuous combustion reaction with oxygen is increased. However, in the case of the embodiment, sulfur (S) reacts with oxygen in the chamber to suppress combustion, and the CO ₂ concentration and total pressure are evaluated to be lower than Comparative Example 1. Also, in the case of the embodiment, the flame disappears simultaneously with the removal of the igniter (torch). This means that the presence of sulfur (S) in the second flame retardant is effective in preventing and preventing flame combustion.

2. Comparison of Example-Comparative Example 2

In the case of Comparative Example 2, the temperature in the chamber is higher than in the Examples. It is considered that Comparative Example 2 (the second flame retardant is not used) is due to the relatively low amount of water produced (since there is little endotherm) since aluminum hydroxide is not present. Also in the case of Comparative Example 2, since sulfur is not present, the CO ₂ concentration and the pressure are evaluated to be higher than in the Examples. In the case of Comparative Example 2, since the second flame retardant, which is an inorganic substance, is not present inside the expanded particles, the combustion takes place continuously between the polymer particles, and the flame existence time becomes very long.

Therefore, it can be confirmed that the presence of aluminum hydroxide and sulfur derived from the second flame retardant is effective in suppressing heat radiation, which is also considered to have an effect of shortening the burning time.

3. Example - Comparison of Comparative Example 3

Comparative Example 3 was to compare the flame retardancy effect according to the presence of the first flame retardant separated from the pulsed wire, and Comparative Example 3 evaluated that the flame retardancy effect was slightly decreased because the first flame retardant was not present on the surface of the expanded particle. .

4. Comparison of tensile strength

It can be seen that the tensile strength of the EPS specimen (molded article) is best evaluated when the surface of the expanded particle is further coated with the third flame retardant (cellulose acetate) (Example 2) as shown in Table 1 above .

As can be seen from the above experimental examples, it can be seen that when both the first and second flame retardants are applied according to the present invention, they have excellent flame retardancy. Particularly, in the case of using the second flame retardant containing aluminum hydroxide and sulfur, it can be seen that it is more effective in preventing combustion and flame retarding than in the case of not using it. Further, when the third flame retardant is further coated, the flame retardancy and the tensile strength of the molded article are improved.

[Example 3]

The molding process of the foamed polystyrene (EPS) specimen (molded product) in a panel shape was carried out in the same manner as in Example 2. Specifically, expanded polystyrene (EPS) particles were prepared in the same manner as in Example 2, and then acetone was sprayed onto the expanded polystyrene (EPS) particles during the process of charging into a molding machine. Thereafter, after standing for about 30 minutes, steam was added to prepare a panel-shaped expanded polystyrene (EPS) specimen (molded product).

The tensile strength (N / cm ² ) of the panel-shaped expanded polystyrene (EPS) specimen (molded product) thus prepared was measured in the same manner as above, and the results are shown in Table 2 below. As shown in the following Table 2, it can be seen that the tensile strength is evaluated to be higher than that in the case of coating acetone before applying steam (Example 3) or when not applying it (Example 2).

                <Tensile Strength Evaluation Results> Remarks
Example 2 Example 3 The tensile strength
(N / cm ² ) 26 31

On the other hand, in separating the resin and the first flame retardant from the waste wire, it is preferable that water is added to the coating mixture obtained after dissolution, and the following examples show this.

[Examples 4 to 10]

In order to investigate the separation efficiency by the addition of water, the following experiment was conducted.

PVC particles, which are mainly used in the manufacture of sheath of waste wire, were prepared. Then, PVC particles were placed in a reactor equipped with a stirrer, and water-soluble methyl ethyl ketone (MEK) was added thereto as an organic solvent. The mixture was stirred for 1 hour while maintaining the temperature in the reactor at about 80 DEG C to completely dissolve the PVC. After dissolution, the PVC was in a gel state.

Next, water was added to the dissolved solution and stirred, and the content of water was varied according to each example. After the addition of water, the mixture was allowed to stand for about 30 minutes. As a result, it was found that the PVC solidified by association (aggregation) and floated to the upper layer. The content of water according to each example is as shown in Table 3 below. The content (parts by weight) of water in the following [Table 3] is based on 100 parts by weight of PVC particles.

Thereafter, the solidified PVC was separated from the solution by filtration and recovered. The recovered PVC was dried and weighed, and the recovery rate (%) of PVC was evaluated. The results are shown together in Table 3 below. At this time, the recovery rate (%) was calculated by the following equation.

[Mathematical Expression]

Recovery rate (%) = [weight of recovered PVC (dry weight of solidified PVC) / weight of PVC particles used before (dissolution of PVC)] x 100

                   &Lt; Evaluation results of recovery of resin (PVC) > Remarks
Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Water content
(Parts by weight) 0 (zero) 10 20 50 80 85 90 Of resin
Recovery rate (%) - 45.8 88.6 98.4 99.2 99.6 99.6

On the other hand, for each of the solutions according to Example 4 and Example 7, fractional distillation was carried out using a distiller. Here, Example 4 is a solution not containing water, which is a solution (PVC: MEK = 1: 2.5 by weight ratio) containing PVC and an organic solvent (MEK). Example 7 is a solution containing water, almost completely removing PVC, which is a solution (water: MEK = 1: 2.5 weight ratio) containing water and organic solvent (MEK). One liter (L) of each of these solutions was subjected to fractional distillation to separate and recover the organic solvent (MEK), and then the recovery (%) of the organic solvent (MEK) was compared. The results are shown in Table 4 below. At this time, a distillation heat source was added to the solution according to Example 4 and Example 7 using an electric heater (heating for 1 hour at 0.8 kW) at the time of distillation.

    &Lt; Evaluation results of recovery rate of organic solvent (MEK) > Remarks Example 4
(PVC + MEK) Example 7
(Water + MEK) MEK
Recovery rate (%) 76.8 92.3

As shown in [Table 3] and [Table 4], it can be seen that when water is added, the PVC is solidified and the separation efficiency is improved. That is, it can be seen that PVC is solidified and can be easily separated by filtration.

Also, in the case of separating the organic solvent (MEK), the mixed solvent of PVC and organic solvent (MEK) showed lower solvent recovery than the mixed solution of water and organic solvent (MEK). It is considered that the recovery rate of the solvent (MEK) is lower than that of the mixed solution of water and organic solvent (MEK) because the solvent (MEK) is contained in the PVC. Thus, it can be seen that the recovery ratio (%) of the solvent (MEK) is improved in the case of the mixed solution of water and organic solvent (MEK). From these results, it can be seen that, at the same solvent recovery (%), the time to apply heat when water is added can be shortened, which means energy saving (reduction in use of distillation heat source).

Therefore, it can be seen that the separation of the resin (PVC) and the recovery of the solvent (MEK) proceed efficiently when water is added, as shown in the above embodiments, and it is also effective in terms of energy efficiency.

Claims (6)

delete In the flame retardant polystyrene type expanded particles,
Styrene type polymers;
A first flame retardant separated from the waste wire;
A second flame retardant; And
A third flame retardant,
Wherein the second flame retardant contains aluminum hydroxide and sulfur,
The third flame retardant is selected from an organic substance having an acetyl group,
The second flame retardant is dispersed in the flame retardant polystyrene type expanded particles,
Wherein the first flame retardant and the third flame retardant are coated on the surface of the flame retardant polystyrene type expanded particles.
A molded article comprising the flame-retardant polystyrene type expanded particles according to claim 2.
Separating the first flame retardant from the waste wire;
Obtaining polystyrene-based expanded particles from a mixture comprising a styrene-based polymer and a second flame retardant;
Obtaining a flame retardant coating liquid comprising a third flame retardant and a first flame retardant separated from the waste wire; And
And coating the surface of the polystyrene type expanded particles with the flame retardant coating liquid,
Wherein the second flame retardant contains aluminum hydroxide and sulfur,
Wherein the third flame retardant is selected from organic materials having an acetyl group.
5. The method of claim 4,
Wherein the step of separating the first flame retardant from the waste wire comprises:
Dissolving a waste wire in an organic solvent to obtain a coating mixture containing a resin and a first flame retardant from a waste wire; And
And a precipitation separation step of causing the first mixture to precipitate the coating mixture through a difference in specific gravity and then separating the first mixture from the coating mixture.
6. The method of claim 5,
The organic solvent is a water-soluble organic solvent having a higher solubility in water than a resin constituting the waste wire,
Wherein the precipitating and separating step includes: a first step of adding water to the coating mixture so that the resin floats up to the upper layer and the first flame retardant is precipitated; And
A resin from the coating mixture; A mixed solution containing an organic solvent and water; And a second step of separating the first flame retardant from the first flame retardant.